Human skin fibroblast collagenase inhibitor. Purification and biochemical characterization

Biochemical and immunohistochemical analysis of tissue inhibitor of metalloproteinases-1 in human sound dentin

Objectives

Matrix metalloproteases (MMPs) are a family of enzymes that operate a proteolytic activity at the level of the extracellular matrix. MMPs are regulated by tissue inhibitors of metalloproteinases (TIMPs) that can ubiquitously bind different enzyme forms. The study aims to identify a morfo-functional association between TIMP-1 and MMP-2 and -9 in human dentin.

Materials and methods

Proteins were extracted from demineralized human sound dentin powder and centrifuged to separate two aliquots with different molecular weights of proteins, higher and lower than 30 kDa. In each aliquot, the evaluation of the presence of TIMP-1/MMP-2 and TIMP-1/MMP-9 was performed using co-immunoprecipitation/immunoblotting analysis. The distribution of TIMP-1, in association with MMP-2 and -9, was investigated using a double immunohistochemical technique. Furthermore, the activity of TIMP-1 was measured by reverse zymography, where acrylamide gel was copolymerized with gelatin and recombinant MMP-2.

Results

Co-immunoprecipitation/immunoblotting analysis showed the association TIMP-1/MMP-2 and TIMP-1/MMP-9 in human sound dentin. Electron microscopy evaluation revealed a diffuse presence of TIMP-1 tightly associated with MMP-2 and -9. Reverse zymography analysis confirmed that TIMP-1 present in human dentin is active and can bind different MMPs isoforms.

Conclusions

The strict association of TIMP-1 with MMP-2 and -9 in situ appeared a constant finding in the human sound dentin.

Clinical relevance

Considering the role of TIMP-1, MMP-2, and MMP-9 within the connective tissues, clinically applicable protocols could be developed in the future to increase or decrease the level of TIMPs in human dentin to regulate the activity of MMPs, contributing to reduce caries progression and collagen degradation.

Investigation of Tissue Inhibitor of Metalloproteinases 1 in Plasma from Colorectal Cancer Patients and Blood Donors by Surface-Enhanced Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Early detection of colorectal cancer (CRC) improves patient survival. Plasma tissue inhibitor of metalloproteinases 1 (TIMP-1) measurements by enzyme-linked immunosorbent assay (ELISA) have been suggested as a new method for the early detection of CRC. To further investigate the nature of TIMP-1 in plasma, surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI TOF MS) was used. TIMP-1 measurements of plasma from 16 healthy donors and 14 CRC patients were performed using TIMP-1 monoclonal antibody in SELDI TOF MS and ELISA. SELDI TOF MS applying an antibody to TIMP-1 revealed that human plasma TIMP-1 has a mass of 25.1 kDa and exhibits several isoforms. Both methods showed increased plasma TIMP-1 values for cancer patients as compared to healthy individuals. The p values for the separation of the groups were 0.0019 for ELISA and <0.0001 for SELDI TOF MS. CRC did not fundamentally affect the appearance of TIMP-1 as evaluated by SELDI TOF MS.

Anti-elastase and anti-collagenase potential of Lactobacilli exopolysaccharides on human fibroblast

Polysaccharides could be used as biodegradable and biocompatible polymers for scaffolds and carriers matrix. Numerous algal, fungi and herbal polysaccharides can attenuate degradation of skin matrix by the inhibition of elastase, collagenase and matrix metalloproteinases (MMPs). In this study, we investigate anti-elastase and anti-collagenase potential of Lactobacilli exopolysaccharides (LEPS) on normal human fibroblast. Among 60 Lactobacilli isolated from herbal plants and dairy products, selected LEPS showed high anti-collagenase (up to 100%), anti-elastase (up to 87%) and antioxidant activity (up to 60%). Most of them had no cytotoxicity effect on fibroblast, and some of them promote cell proliferation (up to 10%). In scratch assay, all the investigated EPS_s stimulated wound healing process in fibroblast (up to 99%). MMP1, MMP2, MMP3, MMP9 and MMP10 were down-regulated significantly and TIMP1 and TIMP2 were up-regulated slightly in LEPS of B9-1 from L. casei with high anti-collagenase and anti-elastase activity; however, no meaningful alteration was observed in MMP_s expression level for LEPS of P35 from L. plantarum with low anti-collagenase and anti-elastase activity. By consideration of high anti-collagenase, anti-elastase, antioxidant activity and wound healing of LEPS, they could be considered as good candidate of skin anti-aging agents for tissue engineering and skin regeneration scaffolds.

Riding the metalloproteinase roller coaster

To many of us in the field, working on matrix metalloproteinases (MMPs) has felt like riding a roller coaster, traveling through times of both excitement and despair. I was fortunate to join the ride when it was a mere carousel of three activities thought to target the proteins that comprise the extracellular matrix (ECM). New technologies brought the thrills of discovery as we uncovered specific proteinase genes and defined specialized activities in different cellular processes. The MMPs and the sister families of "adisintegrin and metalloproteinase" (ADAMs), ADAMs with thrombospondin domains (ADAM-TS), and Astacins are now recognized as key signaling "scissors" that drive rapid changes in a plethora of cellular pathways. My many excellent colleagues and collaborators and I were enthused to contribute to the early development of the field and continue to be amazed at its growth and sophistication. In contrast, the hype and failure of early inhibitor discovery have dogged our standing with the pharmaceutical industry and grant-giving bodies. However, the true believers have kept going, and knowledge of particular functions of MMPs and their contributions to disease progression has progressed. Recognition of the strategic importance of proteinase function should inspire more work harnessing new technologies such as imaging, proteomics, and gene editing to generate a more precise understanding of individual situations. New approaches to inhibitor design and assessment are possible, and the consequent ability to precisely abrogate specific MMP activity could contribute to the fight against a number of pathologies with unmet needs. What a ride it could be!

Dysregulated expression of matrix metalloproteinases and their inhibitors may participate in the pathogenesis of pre-eclampsia and fetal growth restriction

BACKGROUND

Trophoblast invasion into the maternal endometrium serves an important function in human pregnancy. Dysregulation of the finely controlled process of trophoblast invasion can result in a wide spectrum of pregnancy abnormalities.

AIMS

We aimed to elucidate the relationship between the expression of matrix metalloproteinases and pregnancy complication.

STUDY DESIGN

The study group consisted of placental bed biopsy tissues obtained from normal vaginal deliveries (N=15), normal cesarean deliveries (N=15), pre-eclampsia (N=24) and fetal growth restriction (FGR) (N=10). We evaluated the expressions of MMP-2, -8, -9, -11, -19, -15 (MT2-MMP), -16 (MT3-MMP), and -24 (MT5-MMP), as well as TIMP-1 and -3, by applying Western blot and immunohistochemistry methods.

SUBJECTS

Human placental tissues were used for this study.

OUTCOME MEASURES

The expressions of MMP-2, -8, -9, -11, -19, -15 (MT2-MMP), -16 (MT3-MMP), and -24 (MT5-MMP), as well as TIMP-1 and -3 in human placenta tissues.

RESULTS

Compared with those in normal pregnancies, the expression of MMP-2, -8, -9 and -11 was downregulated in villous tissues of pre-eclampsia and FGR cases (p<0.05). TIMP-1 and -3 were increased in pre-eclampsia and FGR (p<0.05). No significant difference was found between normal vaginal deliveries and cesarean deliveries.

CONCLUSIONS

We speculate that the change in invasion-associated proteinase expression will affect placental development and may thus contribute to the development of complicated pregnancies.

Dieckol from Ecklonia cava Regulates Invasion of Human Fibrosarcoma Cells and Modulates MMP-2 and MMP-9 Expression via NF-κB Pathway

The matrix metalloproteinase (MMP) family is involved in the breakdown of extracellular matrix in normal physiological processes, as well as in the disease processes such as arthritis and cancer metastasis. In the present study, dieckol was obtained with high yield from marine brown alga Ecklonia cava (EC), and its effect was assessed on the expression of MMP-2 and -9 and morphological changes in human fibrosarcoma cell line (HT1080). Dieckol inhibited the expression of MMP-2 and -9 in a dose-dependent manner and also suppressed the cell invasion and the cytomorphology in 3D culture system on HT1080 cells. Moreover, dieckol may influence nuclear factor kappa B (NF-κB) pathway without obvious influence on activator protein-1 (AP-1) pathway and tissue inhibitor of metalloproteinases (TIMPs). In conclusion, dieckol could significantly suppress MMP-2 and -9 expression and alter cytomorphology of HT1080 cell line via NF-κB pathway.

Effective treatment of advanced colorectal cancer by rapamycin and 5-FU/oxaliplatin monitored by TIMP-1

AIM

The mTOR-inhibitor rapamycin has shown antitumor activity in various tumors. Bedside observations have suggested that rapamycin may be effective as a treatment for colorectal carcinomatosis.

METHODS

We established an orthotopic syngenic model by transplanting CT26 peritoneal tumors in Balb/C mice and an orthotopic xenograft model by transplanting SW620 peritoneal tumors in nu/nu mice. Expression levels of tissue inhibitor of matrix-metalloproteinases 1 (TIMP-1) in the tumor and serum was determined by enzyme-linked immunosorbent assay.

RESULTS

Rapamycin significantly suppressed growth of syngenic and xenografted peritoneal tumors. The effect was similar with intraperitoneal or oral rapamycin administration. Tumor suppression was further enhanced when rapamycin was combined with 5-fluorouracil and/or oxaliplatin. The combination treatment showed no acute toxicity. TIMP-1 serum levels correlated well (CC = 0.75; P < 0.01) with rapamycin treatment.

CONCLUSIONS

Rapamycin suppressed advanced stage colorectal cancer, even with oral administration. Combining rapamycin with current chemotherapy regimens significantly increased antitumor efficacy without apparent toxicity. The treatment efficacy correlated with serum TIMP-1 levels, suggesting its potential as a surrogate marker in future clinical trials.

Low expression of tissue inhibitor of metalloproteinases-1 (TIMP-1) in glioblastoma predicts longer patient survival

In colorectal cancer and breast cancer a high TIMP-1 level has been shown to correlate with a shorter overall patient survival and it has been suggested that TIMP-1 is involved in tumour invasion, proliferation and apoptosis in different types of cancers. TIMP-1 is known to be expressed in gliomas but whether TIMP-1 is a prognostic marker in gliomas has not previously been investigated. In the present study, the TIMP-1 expression was investigated immunohistochemically in 112 formalin-fixed paraffin embedded astrocytomas and related to tumour grade and overall patient survival by scoring the TIMP-1 immunoreactivity of both tumour cells and blood vessels. Moreover, TIMP-1 in situ hybridisation was performed on ten of the glioblastomas. In the vast majority of the tumours TIMP-1 protein was expressed in both tumour cells and blood vessels. In situ hybridisation for TIMP-1 mRNA on glioblastomas confirmed the immunohistochemical expression of TIMP-1. The percentage of TIMP-1 positive tumour cells and blood vessels as well as the staining intensity varied between tumours of the same grade, but the total staining score increased with tumour grade. The multivariate Cox regression test showed that glioblastoma patients with the lowest TIMP-1 expression had a significantly longer overall survival (HR (95% CI) = 3.2 (1.5-6.7), P = 0.004) when compared to the patients with higher TIMP-1 protein expression. In conclusion, this study showed that low TIMP-1 immunohistochemical expression predicts longer overall survival in glioblastoma patients, suggesting a role for TIMP-1 as a biomarker in glioblastoma.

Biology and potential clinical implications of tissue inhibitor of metalloproteinases-1 in colorectal cancer treatment

Colorectal cancer (CRC) is the second leading cause of cancer-related death in the industrialized world. About half of "curatively" resected patients develop recurrent disease within the next 3-5 years despite the lack of clinical, histological and biochemical evidence of remaining overt disease after resection of the primary tumour. Availability of validated biological markers for early detection, selection for adjuvant therapy, prediction of treatment efficacy and monitoring of treatment efficacy would most probably increase survival. Tissue inhibitor of metalloproteinases-1 (TIMP-1) may be such a marker. TIMP-1 inhibits the proteolytic activity of metalloproteinases, which are centrally involved in tumour invasion and metastases. However, in clinical investigations high tumour tissue or plasma levels of TIMP-1 have shown a strong and independent association with a shorter survival time in CRC patients, suggesting that TIMP-1 could have a tumour-promoting function. Furthermore, measurement of plasma TIMP-1 has been shown to be useful for disease detection, with a high sensitivity and high specificity for early-stage colon cancer. This review describes some basic information on the current knowledge of the biology of TIMP-1 as well as the potential use of TIMP-1 as a biological marker in the management of CRC patients.

Stir-baked Fructus gardeniae (L.) extracts inhibit matrix metalloproteinases and alter cell morphology

Matrix metalloproteinases (MMPs) play vital roles in many pathological conditions, including cancer, cardiovascular disease, arthritis and inflammation. Modulating MMP activity may therefore be a useful therapeutic approach in treating these diseases. Qing-Kai-Ling is a popular Chinese anti-inflammatory formulation used to treat symptoms such as rheumatoid arthritis, acute hypertensive cerebral hemorrhage, hepatitis and upper respiratory tract infection. In this paper, we report that one of the components of Qing-Kai-Ling, Fructus gardeniae, strongly inhibits MMP activity. The IC50 values for the primary herbal extract and water extract against MMP-16 were 32 and 27 microg/ml, respectively. In addition, we show that the herbal extracts influence HT1080 human fibrosarcoma cell growth and morphology. These data may provide molecular mechanisms for the therapeutic effects of Qing-Kai-Ling and herbal medicinal Fructus gardeniae.

Effect of cyclic tensile load on the regulation of the expression of matrix metalloproteases (MMPs -1, -3) and structural components in synovial cells

Synovial cells are reported to colonize synthetic ligament scaffolds following anterior cruciate ligament (ACL) reconstruction but the process leading to ligamentization is poorly understood. The present study investigated the effect of cyclic tensile strain on the expression of genes involved in matrix remodelling in bovine synovial cells seeded onto an artificial ligament scaffold. Synovial cells were seeded and cultured on polyester scaffolds for 3 weeks and subsequently subjected to cyclic tensile strain of 4.5% for 1 hr at frequency of 1 Hz. Changes in the levels of expression of genes for major ligament components (type I and type III collagen) and also metalloproteinases (MMP-1 and MMP-3), and TIMP-1 were examined using RT-PCR. Additionally, metalloproteinase activity was measured using both zymography and collagenase assays. The gene expression of MMP-3 transcripts in the loaded group was almost 3-fold that observed in control group but no differences were observed in other transcripts. Consistent with these findings, MMP-3 activity increased by 85% under mechanical stimulus, and MMP-1 activity showed no changes. Over expression of MMP-3 under cyclic tensile load may mediate the proteolysis of certain substrates surrounding the ligament scaffold. This will play a critical role in facilitating cell migration, proliferation and tissue remodelling by breaking down the provisional tissue formed by the synovium, and by generating factors that induce angiogenesis and chemotactic cell migration.

Identification of alternatively spliced TIMP-1 mRNA in cancer cell lines and colon cancer tissue

TIMP-1 is a promising new candidate as a prognostic marker in colorectal and breast cancer. We now describe the discovery of two alternatively spliced variants of TIMP-1 mRNA. The two variants lacking exon 2 (del-2) and 5 (del-5), respectively, were identified in human cancer cell lines by RT-PCR. The del-2 variant was, furthermore, detected in extracts from 12 colorectal cancer tissue samples. By western blotting additional bands of lower molecular mass than full-length TIMP-1 were identified in tumor tissue, but not in plasma samples obtained from cancer patients. The two splice variants of TIMP-1 may hold important clinical information, and either alone or in combination with measurement of full-length TIMP-1 they may improve the prognostic and/or predictive value of TIMP-1 analyses.

Investigation of Tissue Inhibitor of Metalloproteinases 1 in Plasma from Colorectal Cancer Patients and Blood Donors by Surface-Enhanced Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Early detection of colorectal cancer (CRC) improves patient survival. Plasma tissue inhibitor of metalloproteinases 1 (TIMP-1) measurements by enzyme-linked immunosorbent assay (ELISA) have been suggested as a new method for the early detection of CRC. To further investigate the nature of TIMP-1 in plasma, surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI TOF MS) was used. TIMP-1 measurements of plasma from 16 healthy donors and 14 CRC patients were performed using TIMP-1 monoclonal antibody in SELDI TOF MS and ELISA. SELDI TOF MS applying an antibody to TIMP-1 revealed that human plasma TIMP-1 has a mass of 25.1 kDa and exhibits several isoforms. Both methods showed increased plasma TIMP-1 values for cancer patients as compared to healthy individuals. The p values for the separation of the groups were 0.0019 for ELISA and <0.0001 for SELDI TOF MS. CRC did not fundamentally affect the appearance of TIMP-1 as evaluated by SELDI TOF MS.

Tissue inhibitors of metalloproteinases (TIMPs): their biological functions and involvement in oral disease

Several families of enzymes are responsible for the degradation of extracellular matrix (ECM) proteins during the remodeling of tissues. An important family of such enzymes is that of the matrix metalloproteinases (MMPs). To control MMP-mediated ECM breakdown, tissue inhibitors of metalloproteinases (TIMPs) are able to inhibit MMP activity. A disturbed balance of MMPs and TIMPs is found in various pathologic conditions, such as cancer, rheumatoid arthritis, and periodontitis. The role of MMPs in pathology has been extensively described in the literature. The main focus of this review lies in the biological functions of TIMPs and their occurrence in disease, especially in the head and neck area. Their biological functions and their role in diseases like oral cancers and periodontitis, and in the development of cleft palate, will be discussed. Finally, the diagnostic and therapeutical opportunities of TIMPs will be evaluated.

Comparison of doxycycline and minocycline in the inhibition of VEGF-induced smooth muscle cell migration

Smooth muscle cell migration plays an important role during angiogenesis and vascular remodeling. In this study, we examined the effects of doxycycline and minocycline on vascular endothelial growth factor (VEGF)-induced human aortic smooth muscle cell (HASMCs) migration, and explored the mechanisms in which doxycycline or minocycline inhibit HASMC migration. We demonstrated that both doxycycline and minocycline attain consistent anti-angiogenic effects in the inhibition of HASMC migration via a different signal pathway (p<0.05). This effect is through attenuating VEGF-induced matrix metalloproteinase-9 (MMP-9) activity (p<0.05). Doxycycline could increase tissue inhibitors of metalloproteinases-1 (TIMP-1) expression while minocycline down-regulated PI3K/Akt phosphorylation in HASMC. Our study suggests that doxycycline has a stronger ability to inhibit MMP secretion in HASMC by up-regulating endogenous MMPs inhibitor TIMP-1, while minocycline implements anti-angiogenic effect through inhibiting HASMC migration by down-regulating PI3K/Akt pathway.

Evaluation of an improved tissue inhibitor of metalloproteinase 1 dual monoclonal sandwich immunoassay

BACKGROUND

It has previously been shown that increased levels of plasma tissue inhibitor of metalloproteinase 1 (TIMP-1) is associated with shorter survival for patients with colorectal cancer (CRC). Furthermore, plasma TIMP-1 levels have been found to be elevated in patients with early-stage CRC.

OBJECTIVE

It was the aim of this study to develop a new dual monoclonal antibody (mAb) sandwich immunoassay for TIMP-1 in order to achieve better resolution of non-cancer and cancer plasma specimens.

METHODS

Chemiluminescence immunoassay techniques were used to screen 240 combinations of TIMP-1 mAbs for their ability to interact with each other and to allow for further characterization of the sandwiching antibody pairs. Five mAb pair combinations were selected for assessment of their ability to resolve non-cancerous and cancerous plasma specimens by TIMP-1 measurement. Based on this testing, a final assay format was chosen for further validation. The results for the final assay were compared with measurements obtained in a TIMP-1 ELISA that had previously demonstrated the ability to resolve healthy blood donors and CRC specimens.

RESULTS

The clinical results support that the new dual monoclonal immunoassay has statistical discrimination equivalent to the ELISA. Additionally, the immunoassay had a high reproducibility and specificity.

CONCLUSION

The clinical evaluation of five TIMP-1 immunoassays resulted in the development of a new immunoassay. The new TIMP-1 immunoassay showed superior analytical performance to our previously used ELISA.

Characterization of anti-TIMP-1 monoclonal antibodies for immunohistochemical localization in formalin-fixed, paraffin-embedded tissue

The aim of this study was to evaluate seven anti-TIMP-1 (tissue inhibitor of metalloproteinase-1) monoclonal antibodies by immunohistochemical (IHC) staining of formalin-fixed, paraffin-embedded (FFPE) tissue. Detection of the TIMP-1 protein was studied by IHC in FFPE human archival normal and neoplastic samples. Indirect IHC technique was used, and the seven antibodies (clones VT1, VT2, VT4, VT5, VT6, VT7, and VT8) were tested in various concentrations using different pretreatment protocols. All seven VT antibodies specifically immunostained the cytoplasm of islets of Langerhans cells in normal pancreas, epithelial cells of hyperplastic prostate, tumor cells of medullary thyroid carcinoma, and fibroblast-like cells of malignant melanoma. Specificity of the anti-TIMP-1 antibodies was confirmed by several controls, e.g., Western blotting on proteins extracted from FFPE tissue showed that the VT7 antibody reacted specifically with a protein band of approximately 28 kDa, corresponding to the molecular mass of TIMP-1. However, sensitivity varied with the different antibodies. Use of heat-induced epitope retrieval (HIER) and the VT7 clone applied at low concentrations demonstrated more intense immunoreactivity with the TIMP-1-positive cell types compared to the other six clones. Furthermore, when tested on a range of normal and neoplastic endocrine tissues, the VT7 clone demonstrated immunoreactivity with all neuroendocrine cell types. In conclusion, all seven antibodies detected TIMP-1 protein in various normal and neoplastic FFPE tissues, but one clone, VT7, was superior for IHC staining of TIMP-1 in FFPE tissue sections when using HIER.

Metalloproteinases and their inhibitors are markers of plaque instability

BACKGROUND

Our aim was to investigate the release, activity, and expression of matrix metalloproteinases (MMPs)-1, -2, -3 and -9, and tissue inhibitors of metalloproteinases (TIMPs)-1 and -2 in patients undergoing carotid endarterectomy and to determine whether altered plasma levels of MMPs and TIMPs may be correlated with carotid instability.

METHODS

The carotid plaques of 53 consecutive patients who underwent carotid endarterectomy were classified histologically as stable or unstable. The release of MMPs and TIMPs was analyzed in the serum of patients with stable and unstable carotid plaques, and in 15 age-matched healthy volunteers. The production, activity, and expression of MMPs and TIMPs were determined by Western blotting, zymography, and reverse transcriptase polymerase chain reaction in the carotid specimens.

RESULTS

Twenty-nine (55%) patients had an unstable carotid plaque and 24 (45%) a stable plaque. Plasma levels of MMPs were higher in patients with unstable plaques compared to patients with stable plaques and healthy volunteers ( P < .001), whereas plasma levels of TIMPs were lower in patients with unstable plaques compared to patients with stable plaques and healthy volunteers ( P < .001). In the carotid specimens, we found increased activity, production, and expression of MMPs, and decreased activity, production and expression of TIMPs in unstable plaques compared to stable plaques ( P < .001). After endarterectomy, plasma levels of MMPs and TIMPs in patients with unstable and stable plaques returned to the values found in healthy volunteers.

CONCLUSIONS

Our study demonstrated that an imbalance exists between MMPs and TIMPs in unstable carotid plaques, which is reflected in the plasma levels of these markers. These data may help in selecting patients at high risk for cerebral events.

Establishment and Characterization of 7 New Monoclonal Antibodies to Tissue Inhibitor of Metalloproteinases-1

Tissue inhibitor of metalloproteinases-1 (TIMP-1) plays a pivotal role in tissue remodeling processes, such as inflammation, wound healing and cancer invasion. Experimental results have pointed to a role in angiogenesis, cell proliferation, apoptosis and in malignant transformation. In clinical investigations high tumor tissue or plasma levels of TIMP-1 have been shown to have a strong and independent association with shorter survival time for breast and colorectal cancer patients, respectively. The purpose of this study has been to develop and characterize new anti-TIMP-1 monoclonal antibodies that may be useful in future development of TIMP-1 immunoassays.Peptide-based epitope mapping reveals linear epitopes. Surface plasmon resonance was used to determine antibody affinity and ability of antibodies to sandwich with each other. Antigen recognition was tested using ELISA and a chemiluminescence microtiter immunoassay format. Three antibodies recognized linear peptides. Estimated antibody affinities for TIMP-1 ranged from 6.6 x 10(8) to>10(10) 1/M. Antibodies demonstrated different abilities in 'capture' and 'detection' positions in the sandwich experiment. All antibody pairs bound TIMP-1:ProMMP-9 complexes. TIMP-1:MMP-9 complexes were marginally reactive with five antibody pairs. The results suggest that the antibodies are unique. They may be useful in designing assays that recognize various forms of TIMP-1. Future studies will clarify whether the use of different combinations of antibodies will increase the clinical value of TIMP-1 measurements in the treatment of cancer patients.

Tissue inhibitor of metalloproteinase-3 downregulation in lymphangioleiomyomatosis: potential consequence of abnormal serum response factor expression

Pulmonary lymphangioleiomyomatosis (LAM) is characterized by abnormal smooth muscle-like cell proliferation leading to tissue destruction and cyst formation. We demonstrate that serum response factor (SRF), a critical smooth muscle transcription factor, is overexpressed in LAM cells. To determine whether abnormal SRF levels might have a pathogenic role in LAM, we transfected SRF into mouse lung fibroblasts and performed a cDNA array analysis. High SRF level upregulated the expression of matrix metalloproteinase (MMP)-2 and MMP-14, two MMPs previously shown to be increased in LAM. In addition, SRF down-regulated tissue inhibitor of metalloproteinase (TIMP)-3, one of their inhibitors. TIMP-3 inhibition was further confirmed by reverse transcriptase/polymerase chain reaction, immunoblotting, and immunostaining of human lung fibroblasts transfected with SRF fused to DsRed2 (a red variant of green fluorescent protein). To determine the in vivo significance of our findings, we immunostained 12 LAM cases for TIMP-3. In eight of them, TIMP-3 was ubiquitously present in normal lung parenchyma, but it was absent in LAM lesions. In the remaining cases, including two out of five normal control lungs, the antibody immunoreacted exclusively with elastin, probably due to suboptimal tissue processing. Because timp-3-null mice develop spontaneous emphysema, our findings suggest that SRF-mediated TIMP-3 inhibition might contribute to the tissue damage seen in LAM.

Evaluation of phenylboronate agarose for industrial-scale purification of erythropoietin from mammalian cell cultures

The search for novel, cost-effective ways to produce erythropoietin (Epo), the world top-selling biopharmaceutical, is a major challenge for today's biotechnology industry. However, Epo's high glycosylation content (almost 40% of total mass) and the requirement for sialic acid for optimal in vivo activity still make mammalian cells the expression system of choice. In contrast to the abundance of reports on Epo production, robust, cost-effective methods for large-scale Epo purification can hardly be found in literature. To fill this gap, we describe here a process specifically studied for industrial-scale purification of the protein. Our method is based on the ability of phenylboronate agarose (PBA) to form reversible complexes with 1,2-cis-diol-containing molecules, like sugars in glycoproteins. Finding that additional factors (i.e., ionic and hydrophobic interactions) contribute to the Epo-PBA binding reaction, chromatography conditions have been optimized in scale-down experiments to improve selectivity and yield. As a result, the high performance of affinity chromatography has been achieved using a support possessing the robustness, chemical stability and low cost of a small synthetic ligand. By adding an anion exchange chromatography step and gel filtration for polishing, a pure and active product can easily be obtained by an integrated, start-to-end process optimized for industrial-scale operations.

Regulation of tissue inhibitors of metalloproteinase-1 gene expression by cytokines in human gingival fibroblasts

Tissue inhibitors of metalloproteinase (TIMP) are important participants in various physiological processes that involve tissues remodeling. They help maintain a delicate balance between physiological degradation and synthesis of the extracellular matrix. A better understanding of TIMP activity will be helpful in understanding the etiology of periapical lesions and their means of treatment. The fibroblast is a prominent cellular component of the periapical tissues. The potential implications of cytokine-mediated tissue destruction still remain to be elucidated. The purpose of this study was to determine the effects of interleukin (IL)-1alpha and transforming growth factor (TGF)-beta on the expressing of TIMP-1 by primary gingival fibroblast cultures. After exposure to cytokines for 8 h, total RNA in gingival fibroblasts was isolated and evaluated by reverse-transcriptase polymerase chain reaction. Densitometric analysis of the TIMP-1 mRNA gene expression, after normalization by beta-actin, demonstrated that exposure to IL-1alpha resulted in a decreased level of TIMP-1 mRNA compared with the control groups. However, the TIMP-1 mRNA was up-regulated by TGF-beta. In addition, when the cells were cultured in combination with TGF-beta (1 ng/ml) and IL-1alpha for 8 h, the level of TIMP-1 mRNA was dramatically reduced. These results demonstrated that in human periapical tissue cytokines differentially and specifically regulate expression of TIMP-1 mRNA. An understanding of the actions of cytokines on gingival fibroblasts may result in new therapies to augment current treatment of periapical lesions.

Up-regulation of MMP-8 and MMP-9 activity in the BALB/c mouse spinal cord correlates with the severity of experimental autoimmune encephalomyelitis

Induction of EAE can be inhibited or repressed by administration of soluble metalloproteinase inhibitors. We studied the matrix metalloproteinase (MMP) and their tissue inhibitor (TIMP) expression pattern in experimental autoimmune encephalomyelitis (EAE) of the resistant Th2 prone BALB/c mouse, where the disease can be induced with ultrasound-emulsified antigen/adjuvant (son-ag), but not with conventional technique (syr-ag). We found highly elevated expression of MMP-8 (neutrophil collagenase) mRNA and protein in diseased son-ag challenged mice, colocalizing to neutrophil infiltrates found in brain and extensively in the spinal cord submeningeal space. MMP-8 expression has not been found previously in sensitive mouse strains. The infiltrates stained positive also for MMP-9 protein, and brain homogenates from corresponding mice showed MMP-9 activity during overt disease (days 12-16 post-immunization). TIMP-1 gene expression could be detected in CNS samples from diseased son-ag challenged mice but not in syr-ag or control mice, and the TIMP-1 protein colocalized with GFAP-staining. In contrast, in syr-ag mice both TIMP-2 and TIMP-3 gene expression in the spinal cords was elevated. The results show that sonication, but not extrusion, creates an adjuvant formula potent in activating the matrix metalloproteinase cascade similar to sensitive mouse strains, strongly implicating their role in EAE induction in this Th2 prone strain. The study provides the basis for establishment of MMP-specific therapy in this model.

Increased tissue inhibitor of metalloproteinase-1 expression and inhibition of gelatinase A activity in buccal mucosal fibroblasts by arecoline as possible mechanisms for oral submucous fibrosis

Oral submucous fibrosis (OSF) is a pre-malignant fibrotic lesion of the mouth in areca quid chewers. It is probably a consequence of disturbances in the hemeostatic equilibrium between synthesis and degradation of extracellular matrix molecules (ECM). To date, there has been little research about the role of tissue inhibitors of metalloproteinase (TIMPs) and matrix metalloproteinases (MMPs) in the pathogenesis of OSF. In the present study, we examined the activity of TIMPs from cells cultured from OSF and normal buccal mucosa. OSF specimens were found to have higher TIMP-1 expression than normal buccal mucosal fibroblasts (BMFs) by Western blots. To verify whether arecoline, a major areca nut alkaloid, could affect TIMP or MMP production by human BMFs, Western blots and gelatine zymography were used. Arecoline was found to elevate TIMP-1 expression at the concentration level under 20 microg/ml in a dose-dependent manner. The amount of TIMP-1 was about 2.7 fold at a concentration level of 10 microg/ml compared with control. From gelatin zymograms, the main gelatinolytic proteinase secreted by the human BMFs was MMP-2, and only minimal amounts of MMP-9 could be detectable from zymogram. In addition, arecoline was found to inhibit MMP-2 secretion and production at the concentration level of 40 microg/ml. The gelatinolytic activity of MMP-2 was about 54% at a concentration level of 80 microg/ml compared with control. Taken together, it was found that arecoline acted not only as an inhibitor on gelatinolytic activity of MMP-2, but also a stimulator for TIMP-1 activity. These synergistic effects may contribute to the ECM components accumulation in the areca quid associated OSF.

Induction of MMP-9 in normal human bronchial epithelial cells by TNF-alpha via NF-kappa B-mediated pathway

In this study, we determined whether the proinflammatory cytokines tumor necrosis factor (TNF)-alpha and interleukin-1 beta contribute to the regulation of matrix metalloproteinase (MMP)-9 in human bronchial epithelial cells and whether the induction of MMP-9 is regulated by the transcription factor nuclear factor (NF)-kappa B. We demonstrated that TNF-alpha induced MMP-9 at both the protein and mRNA levels in human bronchial epithelial cells and that interleukin-1 beta did not. In contrast, induction of the tissue inhibitor of metalloproteinase-1 by TNF-alpha was less than that of interleukin-1 beta. Increased expression of MMP-9 and NF-kappa B activation induced by TNF-alpha were inhibited by pyrrolidine dithiocarbamate and N-acetyl-L-cysteine but were not inhibited by curcumin. These results suggest that TNF-alpha induces the expression of MMP-9 in human bronchial epithelial cells and that this induction is mediated via the NF-kappa B-mediated pathway.

Expression of MMP2, MMP9, MT1-MMP, TIMP1, and TIMP2 mRNA in valvular lesions of the heart

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play an important role in several diseases. This study was undertaken to investigate the mRNA synthesis of MMP2, MMP9, membrane-type 1 (MT1)-MMP, and matrix metalloproteinase inhibitors TIMP1 and TIMP2 by in situ hybridization in a set of heart mitral and aortic valves operatively removed due to degenerative or inflammatory valvular diseases. The material consisted of 21 valves, eight with endocarditis and 13 with a degenerative valvular disease. The samples were studied by in situ hybridization with specific probes for MMP2, MMP9, MT1-MMP, TIMP1, and TIMP2. Synthesis of MMP2 mRNA was found in seven valves, five with endocarditis and two with degenerative valvular disease. Signals for MMP9 mRNA were found in two cases with endocarditis and five cases with degenerative valvular disease. No signal for MT1-MMP mRNA was found in the lesions. TIMP1 mRNA, on the other hand, was found in 17 cases, both endocarditis and degenerative valvular disease. TIMP2 mRNA was found in three cases of endocarditis. The signals for MMP2, MMP9, TIMP1, and TIMP2 mRNA were localized in endothelial cells and in fibroblast-like cells expressing alpha-smooth muscle actin, thus showing myofibroblast-type differentiation. The results show that matrix metalloproteinases MMP2 and MMP9, and matrix metalloproteinase inhibitors TIMP1 and TIMP2 mRNAs are synthesized in diseased valves and suggest that they may contribute to matrix remodelling in valvular disease.

The roles of cytokines in photoaging

Photoaging comprises characteristic changes in appearance and function of the skin as a result of repeated sun exposure rather than to passage of time alone. Clinically, wrinkles, laxity, coarseness, mottled pigmentation, lentigenes, teleangiectasia and purpura characterize photoaging. Photoaging is also characterized by atrophy, fibrotic depigmented areas termed pseudoscars, and ultimately premalignant and malignant neoplasms on sun exposed areas. These features are the result of ultraviolet radiation (UVR) in the sunlight. UVR stimulates and activates various cells and tissues to produce and release cytokines that may play a significant role in the process of photoaging. However, cytokines are the major orchestrators of the host defense processes and are involved in response to exogenous and endogenous insults, and repair and restore homeostasis. Therefore, cytokines may be beneficial in the course of photoaging. Considering the complex cytokine network in the skin, focus will be taken on several subjects that have seen major changes during the last few years. I will first outline our knowledge of cytokines in the skin together with their functions, then review our knowledge of the involvement of cytokines in photoaging, and finally summarize the defense system related to cytokines.

Antisense oligonucleotide of tissue inhibitor of metalloproteinase-1 induces the plasminogen activator activity in periodontal ligament cells

BACKGROUND

Matrix metalloproteinases (MMPs), produced by both infiltrating and resident cells of the periodontium, play a role in physiologic and pathologic events. It is recognized that an imbalance between activated MMPs and their endogenous inhibitors leads to pathologic breakdown of the extracellular matrix during periodontitis. Although it is known that pro-MMPs are activated by the plasminogen activator (PA)/plasmin system, and that the activated MMPs are inactivated by tissue inhibitor of metalloproteinases (TIMPs), participation of TIMPs in the PA/plasmin system has not been defined.

METHODS

We investigated the effects of the antisense oligonucleotide, consisting of a 21-base sequence from the human TIMP-1 gene including the first ATG initiation codon, on PA/plasmin activities in the cultured medium of periodontal ligament (PDL) fibroblastic cells. Antisense or sense oligonucleotides were directly added into cell-cultured medium, and enzyme activities from the PDL cells were measured.

RESULTS

Antisense TIMP-1 oligonucleotide specifically stimulated the PA activity dose-dependently. Other oligonucleotides, sense TIMP-1 or antisense TIMP-2, did not affect PA activity in PDL cells. The PA activity increased by antisense TIMP-1 oligonucleotide was due to an increase of urokinase-type PA (uPA) protein, but not that of tissue-type PA by means of immunoblotting. Furthermore, the stimulation of PA activity in the conditioned medium by adding antisense oligonucleotide for TIMP-1 was not due to the decreasing levels of PA inhibitor-1, an inhibitor of PA.

CONCLUSIONS

TIMP-1 controls the synthesis of uPA in the PDL cells. Control of the TIMP-uPA system is important in inflammatory periodontal ligament healing.

Physiological roles of matrix metalloproteinases: implications for tumor growth and metastasis

Physiological processes involving remodelling of the extracellular matrix, such as wound healing, embryogenesis, angiogenesis, and the female reproductive cycle, require the activity of matrix metalloproteinases (MMPs). This group of proteases degrades basal membranes and connective tissues and plays an essential role in the homeostasis of the extracellular matrix. An imbalance in the expression or activity of MMPs can have important consequences in diseases such as multiple sclerosis, Alzheimer's disease, or the development of cancers. Because of the pathophysiological importance of MMPs, their activity is highly controlled in order to confine them to specific areas. An activation cascade, initiated by the proteolysis of plasminogen, cleaves proMMPs, and every step is controlled by specific activators or inhibitors. MMPs destabilize the organization of the extracellular matrix and influence the development of cancer by contributing to cell migration, tumor cell proliferation, and angiogenesis. Accordingly, these proteases possess an important role in cell-matrix interactions by affecting fundamental processes such as cell differentiation and proliferation. Therefore, the characterization of MMPs involved in specific types and stages of tumors will significantly improve the diagnosis and treatment of these cancers in humans.Key words: matrix metalloproteinases, physiology, cancer, cell invasion, extracellular matrix.

Identification of the tissue inhibitor of metalloproteinases-2 (TIMP-2) binding site on the hemopexin carboxyl domain of human gelatinase A by site-directed mutagenesis. The hierarchical role in binding TIMP-2 of the unique cationic clusters of hemopexin modules III and IV

Cell surface activation of progelatinase A occurs in a quaternary complex with the tissue inhibitor of metalloproteinases-2 (TIMP-2) and two membrane-type matrix metalloproteinases. We have mutated the unique cationic clusters found in hemopexin modules III and IV of the carboxyl domain (C domain) of human gelatinase A to determine their role in binding TIMP-2. Twelve single, double, and triple site-directed mutations were produced that exhibited different TIMP-2 binding properties. Notably, single alanine substitutions at Lys547 and Lys617 reduced TIMP-2 binding by an order of magnitude from that of the recombinant wild-type C domain. Mutations that completely disrupted the C domain.TIMP-2 interaction were K558A/R561A, K610T/K617A, and K566A/K568A/K617A. A triple mutation, K566A/K568A/K575A, having TIMP-2 binding indistinguishable from the wild-type C domain (Kd 3.0 x 10(-8) M), showed that simple reduction of net positive charge does not reduce TIMP-2 affinity. Because the double mutation K566A/K568A also did not alter TIMP-2 binding, these data do not confirm previously reported chimera studies that indicated the importance of the triple lysine cluster at positions 566/567/568 in TIMP-2 binding. Nonetheless, a subtle role in TIMP-2 interaction for the 566/567/568-lysine triad is indicated from the enhanced reduction in TIMP-2 binding that occurs when mutations here were combined with K617A. Thus, these analyses indicate that the TIMP-2 binding surface lies at the junction of hemopexin modules III and IV on the peripheral rim of the gelatinase A C domain. This location implies that considerable molecular movement of the TIMP-2. C domain complex would be needed for the bound TIMP-2 to inhibit in cis the gelatinase A active site.

Glycosylation and NH2-terminal domain mutants of the tissue inhibitor of metalloproteinases-1 (TIMP-1)

Mutants in the tissue inhibitor of metalloproteinases-1 (TIMP-1) protein have been created by site-directed mutagenesis and expressed in HeLa cells, using a recombinant vaccinia virus system. Removal of either or both glycosylation sites yielded proteins which retained wild-type inhibitory activity against both human fibroblast-type collagenase (FIB-CL) and Mr 72000 gelatinase (GL). However, the double glycosylation mutant protein was expressed at a level that was 2-4-fold lower than that of the wild-type or the single site glycosylation mutants. The 'tiny-TIMP' COOH-terminal deletion mutant that lacks the last 57 residues was also inhibitory, but the dose-response curve suggested that the interaction with the Mr 72000 gelatinase had been altered. A number of replacement mutants in the highly conserved NH2-terminal domain, including replacement of P5A and P8A or a double mutation in the VIRAK sequence which is absolutely conserved in all TIMPs in all species (VIRAK to VIAAA), also yielded functional proteins capable of inhibiting FIB-CL and Mr 72000 GL and of forming SDS-resistant complexes with FIB-CL. None of the above manipulations abolished inhibitory function suggesting that binding of the inhibitor by the enzyme involves multiple interactions.

Collagenase-1 complexes with alpha2-macroglobulin in the acute and chronic wound environments

The purpose of this study was to examine the appearance and activation of collagenase-1 (MMP-1) in the wound environment. We found that MMP-1 accumulates in the fluid phase of the burn wound environment within 2 d of injury and reaches maximal levels by day 4. Two forms of the enzyme were evident; one that corresponded to proMMP-1 and another that corresponded to a group of high molecular mass (approximately 200 kDa and >200 kDa doublet) MMP-1 containing complexes. ProMMP-1 and MMP-1 containing complexes also occurred in wound fluid from venous stasis ulcers, but neither was detected in mastectomy fluid or in plasma. Levels of the proteinase inhibitor alpha2-macroglobulin in burn fluid and chronic ulcer wound fluid were almost as high as in plasma, and the high molecular mass MMP-1 containing complexes in burn fluid appeared to result from binding between alpha2-macroglobulin and activated MMP-1. These observations provide direct evidence that active MMP-1 in the fluid phase of the wound environment becomes complexed to alpha2-macroglobulin.

Divergent regulation of 92-kDa gelatinase and TIMP-1 by HBECs in response to IL-1beta and TNF-alpha

In this study, we addressed the question of whether human bronchial epithelial cells (HBECs) contribute to the regulation of 92-kDa gelatinase activity by secreting tissue inhibitor of metalloproteinase (TIMP)-1. We investigated expression of 92-kDa gelatinase and TIMP-1 in response to lipopolysaccharide (LPS) and to the proinflammatory cytokines interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha. Confluent HBECs from explants were cultured in plastic dishes coated with type I and III collagen. We demonstrated that TIMP-1 was expressed at both the protein and mRNA levels by primary cultures of HBECs. Gelatin zymography of HBEC-conditioned media showed that exposure of HBECs to LPS, IL-1beta, or TNF-alpha induced a twofold increase in the latent form of 92-kDa gelatinase production, as well as its activation. Also, quantitative reverse transcriptase (RT)-polymerase chain reaction (PCR) demonstrated a twofold increase in the 92-kDa mRNA level in response to both cytokines. In contrast, TIMP-1 production evaluated by immunoblotting was unchanged in the presence of LPS and IL-1beta and was clearly decreased in the presence of TNF-alpha. Quantitative RT-PCR demonstrated that TIMP-1 mRNA levels remained unchanged in response to LPS or IL-1beta but decreased by 70% in the presence of TNF-alpha. All of these results strongly suggest that the control mechanisms regulating the expression of 92-kDa gelatinase and TIMP-1 by HBECs in response to inflammatory stimuli are divergent and result in an imbalance between 92-kDa gelatinase and TIMP-1 in favor of the metalloproteinase. Such an imbalance may contribute significantly to acute airway inflammation.

Initiation of osteoclast bone resorption by interstitial collagenase

Osteoclasts form an acidic compartment at their attachment site in which bone demineralization and matrix degradation occur. Although both the cysteine proteinases and neutral collagenases participate in bone resorption, their roles have remained unclear. Here we show that interstitial collagenase has an essential role in initiating bone resorption, distinct from that of the cysteine proteinases. Treatment of osteoclasts with cysteine proteinase inhibitors did not affect the number of resorption lacunae ("pits") formed on the surface of dentine slices, but it generated abnormal pits that were demineralized but filled with undegraded matrix. Treatment with metalloproteinase inhibitors did not alter the qualitative features of lacunae, but it greatly reduced the number of pits and surface area resorbed. Treatment of bone cells with an inhibitory anti-rat interstitial collagenase antiserum reduced bone resorption markedly. In the presence of collagenase inhibitors, resorption was restored by pretreatment of dentine slices with rat interstitial collagenase or by precoating the dentine slices with collagenase-derived gelatin peptides or heat-gelatinized collagen. Immunostaining revealed that interstitial collagenase is produced at high levels by stromal cells and osteoblasts adjacent to osteoclasts. These results indicate that interstitial collagenase can function as a "coupling factor," allowing osteoblasts to initiate bone resorption by generating collagen fragments that activate osteoclasts.

In situ hybridization study on tissue inhibitors of metalloproteinases (TIMPs) mRNA-expressing cells in human inflamed gingival tissue

This study presents the exact cell types and localization of tissue inhibitors of metalloproteinases (TIMPs) production sites in periodontal diseased gingiva by means of in situ hybridization. Gingival tissue specimens were fixed, embedded and hybridized in situ with specific digoxigenin-labeled cRNA probes (386 and 496 bp). TIMP-1 and -2 mRNAs were expressed on macrophages, mononuclear cells, capillary endothelial cells and some fibroblasts throughout the gingival tissue. In periodontitis, TIMP-1 and -2 mRNA-expressing cells showed significantly different localization. TIMP-1 mRNA was broadly observed in the gingival connective tissue while TIMP-2 mRNA was predominantly expressed in the connective tissue adjacent to the pocket epithelium (p < 0.01). Fewer TIMPs mRNA were observed in minimal gingivitis than in periodontitis, especially in the middle zone of gingival tissue. Thus, TIMP-1 and TIMP-2 mRNA was detected differentially and site-specifically in periodontal diseased gingival tissue.

Specific, high affinity binding of tissue inhibitor of metalloproteinases-4 (TIMP-4) to the COOH-terminal hemopexin-like domain of human gelatinase A. TIMP-4 binds progelatinase A and the COOH-terminal domain in a similar manner to TIMP-2

The binding properties of the newly described tissue inhibitor of metalloproteinases-4 (TIMP-4) to progelatinase A and to the COOH-terminal hemopexin-like domain (C domain) of the enzyme were examined. We present evidence for the first time of a specific, high affinity interaction between TIMP-4 and the C domain of human gelatinase A and show that TIMP-4 binds both progelatinase A and the C domain in a similar manner to that of TIMP-2. Saturable binding of recombinant C domain to TIMP-4 and to TIMP-2 but not to TIMP-1 was demonstrated using a microwell protein binding assay. The recombinant collagen binding domain of gelatinase A, comprised of the three fibronectin type II-like repeats, did not bind to TIMP-4, indicating that binding is mediated selectively by the C domain. Binding to TIMP-4 was of high affinity with an apparent Kd of 1.7 x 10(-7) M but slightly weaker than that to TIMP-2 (apparent Kd of 0.66 x 10(-7) M). Affinity chromatography confirmed the TIMP-4-C domain interaction and also showed that the complex could not be disrupted by 1 M NaCl or 10% dimethyl sulfoxide, thereby further demonstrating the tight binding. To verify the biological significance of this interaction, binding of full-length progelatinase A to TIMP-4 was investigated. TIMP-4 and TIMP-2 but not TIMP-1 bound specifically to purified TIMP-2-free human recombinant full-length progelatinase A and to full-length rat proenzyme from the conditioned culture medium of ROS 17/2.8 cells. Preincubation of the C domain with TIMP-2 was found to reduce subsequent binding to TIMP-4 in a concentration-dependent manner. Competition between TIMP-2 and TIMP-4 for a common or overlapping binding sites on the gelatinase A C domain may occur; alternatively TIMP-2 may prevent the binding of TIMP-4 by steric hindrance or induction of a conformational change in the C domain. We propose that the binding of progelatinase A to TIMP-4 represents a third TIMP-progelatinase interaction in addition to that of progelatinase A with TIMP-2 and progelatinase B with TIMP-1 described previously. This new phenomenon may be of important physiological significance in modulating the cell surface activation of progelatinase A.

Tissue inhibitor of metalloproteinase-1 and tissue inhibitor of metalloproteinase-2 expression in human amnion mesenchymal and epithelial cells

OBJECTIVE

This study was conducted to define the cellular site of expression of tissue inhibitor of metalloproteinase-1 and tissue inhibitor of metalloproteinase-2 in human amnion by an evaluation of the levels of messenger ribonucleic acids in separated amnion epithelial and mesenchymal cells and to ascertain whether amnion epithelial and mesenchymal cells maintained in culture continue to express tissue inhibitor of metalloproteinase messenger ribonucleic acids.

STUDY DESIGN

Human placentas and fetal membranes were obtained immediately after delivery. Amnion tissue was separated from chorion laeve and either frozen immediately (-80 degrees C) or processed by differential enzymatic treatment to separate the epithelial and mesenchymal cells, which were frozen (-80 degrees C) or else plated and maintained in monolayer culture. The levels of tissue inhibitor of metalloproteinase types 1 and 2 messenger ribonucleic acid were evaluated by Northern analyses of total ribonucleic acid extracted from amnion tissue, freshly separated epithelial and mesenchymal cells, and epithelial and mesenchymal cells in monolayer culture.

RESULTS

Tissue inhibitor of metalloproteinase types 1 and 2 messenger ribonucleic acids were detected by Northern analysis in freshly isolated amnion tissues from midtrimester and term pregnancies. The major species of tissue inhibitor of metalloproteinase-1 messenger ribonucleic acid was 0.9 kb in length; a minor species of approximately 3.5 kb also was present. Tissue inhibitor of metalloproteinase-2 messenger ribonucleic acids of 3.5 and 1.0 kb and of similar intensity were also detected. The levels of type 1 messenger ribonucleic acid were not different in amnion tissues obtained at term or during the midtrimester of pregnancy. The levels of tissue inhibitor of metalloproteinase type 2 messenger ribonucleic acids in amnion tissue most commonly were greater at term than in tissues obtained during the midtrimester. The level of type 1 messenger ribonucleic acid in mesenchymal cells was appreciably greater than that in epithelial cells, and this difference was maintained during culture of these cells. The level of type 2 messenger ribonucleic acid was similar in both cell types and was maintained during culture. The levels of type 1 or 2 messenger ribonucleic acids were not affected by treatment of amnion epithelial or mesenchymal cells in culture with a variety of test agents, including steroid hormones, cytokines, and growth factors.

CONCLUSION

The amnion mesenchymal cells are the primary source of tissue inhibitor of metalloproteinase-1 in human amnion, whereas both cell types have the potential to produce tissue inhibitor of metalloproteinase-2.

Ultraviolet B wavelength dependence for the regulation of two major matrix-metalloproteinases and their inhibitor TIMP-1 in human dermal fibroblasts

The wavelength dependence for the regulation of two major matrix-metalloproteinases, interstitial collagenase (MMP-1) and stromelysin-1 (MMP-3), and their major inhibitor, tissue inhibitor of metalloproteinases (TIMP-1), was studied in human dermal fibroblasts in vitro. Monochromatic irradiation at 302, 307, 312 and 317 nm with intensities ranging from 20 to 300 J/m2 increased MMP-1 and MMP-3 mRNA steady-state levels and the secretion of the corresponding proteins up to 4.4-fold, whereas almost no increase was observed at wavelengths < 290 nm. In contrast, the synthesis of TIMP-1 increased only marginally. This imbalance may contribute to the severe connective tissue damage related to photoaging of the skin. The wavelengths responsible for MMP-1 and MMP-3 induction reported here are distinct from the absorption spectrum of DNA and are different from results previously reported in the literature. Importantly, they overlap with wavelengths whose intensity is predicted to increase on the earth's surface upon ozone depletion. Intensities and particular wavelengths used in our studies in vitro can be absorbed readily by fibroblasts within the skin in vivo and, thus, are relevant for risk assessment and development of protective agents.

Overexpression of tissue inhibitor of matrix metalloproteinase-1 inhibits vascular smooth muscle cell functions in vitro and in vivo

Arterial smooth muscle cells (SMCs) are in a quiescent growth state under normal physiological conditions, but they can be stimulated to proliferate and migrate from one tissue compartment to another if the vessel is injured. This response might require a selective and focal increase in tissue degradation, which might be mediated through the increased production of matrix metalloproteinases (MMPs). Blockade of MMP activity might therefore inhibit the SMC response to injury. To test this hypothesis, we developed clones of rat SMCs that overexpress baboon tissue inhibitor of matrix metalloproteinase-I (TIMP-1), using retrovirally mediated gene transfer, and characterized the functional capacity of these cells in vitro and in vivo. SMCs transduced with the TIMP-1 vector (LTSN) grew more slowly and also migrated through a gel matrix in a Boyden chamber assay more slowly than the vector alone (LXSN) cells. The conditioned medium from LTSN cells completely inhibited the platelet-derived growth factor-BB-induced migration of normal SMCs across a matrix-coated filter, while the LXSN cell conditioned medium had no effect. The inhibitor activity in the LTSN conditioned medium could be neutralized with an antibody to TIMP-1. In vivo, local overexpression of TIMP-1 using LTSN cells implanted onto balloon-injured rat carotid artery inhibited intimal hyperplasia. Neutralizing antibodies against TIMP-1 suppressed the effect of LTSN cell seeding on intimal thickening. These data support the conclusion that the process of SMC activation leading to a thickened intima is dependent on MMP activity and that TIMP-1 could be utilized to inhibit this process.

Ultraviolet B wavelength dependence for the regulation of two major matrix-metalloproteinases and their inhibitor TIMP-1 in human dermal fibroblasts

The wavelength dependence for the regulation of two major matrix-metalloproteinases, interstitial collagenase (MMP-1) and stromelysin-1 (MMP-3), and their major inhibitor, tissue inhibitor of metalloproteinases (TIMP-1), was studied in human dermal fibroblasts in vitro. Monochromatic irradiation at 302, 307, 312 and 317 nm with intensities ranging from 20 to 300 J/m2 increased MMP-1 and MMP-3 mRNA steady-state levels and the secretion of the corresponding proteins up to 4.4-fold, whereas almost no increase was observed at wavelengths < 290 nm. In contrast, the synthesis of TIMP-1 increased only marginally. This imbalance may contribute to the severe connective tissue damage related to photoaging of the skin. The wavelengths responsible for MMP-1 and MMP-3 induction reported here are distinct from the absorption spectrum of DNA and are different from results previously reported in the literature. Importantly, they overlap with wavelengths whose intensity is predicted to increase on the earth's surface upon ozone depletion. Intensities and particular wavelengths used in our studies in vitro can be absorbed readily by fibroblasts within the skin in vivo and, thus, are relevant for risk assessment and development of protective agents.

Photosensitization of uroporphyrin augments the ultraviolet A-induced synthesis of matrix metalloproteinases in human dermal fibroblasts

Porphyria cutanea tarda is characterized by severe connective tissue damage in sun-exposed skin. The regulated synthesis and degradation of the extracellular matrix by various matrix metalloproteinases (MMPs) determine its amount and composition within the skin. In this study, we therefore asked whether long-wave ultraviolet irradiation (340-450 nm) in conjunction with uroporphyrin I could modulate the synthesis of MMPs with substrate specificities for dermal (collagens I, III, V; proteoglycans) and basement membrane components (collagens IV, VII; fibronectin; laminin) and whether synthesis of the counteracting tissue inhibitor of metalloproteinases is also affected. After irradiation of uroporphyrin-pretreated fibroblasts, specific mRNAs of MMP-1 and MMP-3 increased concomitantly up to 2.7-fold compared with ultraviolet-irradiated cells and up to 10-fold compared with mock-irradiated or uroporphyrin I-treated controls. In contrast, mRNA levels of tissue inhibitor of metalloproteinases remained unaltered. Similar results were obtained by immunoprecipitation. Gelatin and casein zymography revealed increased proteolytic activity of MMP-2 and MMP-3 in blister fluids of patients with porphyria cutanea tarda, indicating that similar events may occur in vivo. Using deuterium oxide as enhancer and sodium azide as quencher of singlet oxygen, we could increase or reduce MMP synthesis, suggesting that singlet oxygen is the major intermediate in the upregulation of MMPs after irradiation of uroporphyrin-pretreated fibroblasts. Taken together, our results show that ultraviolet irradiation alone, and to a greater extent in conjunction with uroporphyrin I, results in an unbalanced synthesis of MMPs that may contribute to the destruction of the dermis and basement membrane, leading to blistering and accelerated photoaging in porphyria cutanea tarda patients.